1. Field of the Invention
The invention relates to electric or electronic animal traps, and relates more particularly to an animal trap adapted to catch and electrocute a targeted animal, and also to rearm in the event the continuing presence of the animal is not detected upon completion of a killing cycle.
2. The Prior Art
Incline plane animal traps have been available for over one hundred years. The commercial embodiments of such traps currently available commonly comprise a housing defining an enlarged enclosure with one, or perhaps two, inclined plane trap assemblies communicating the interior of the enclosure with the exterior of the housing via an elongated passageway. An inclined plane tilting floor member is positioned in the passageway of each trap assembly and is adapted to lift a door to block the entrance opening when the animal passes beyond a pivot point, thereby limiting escape from the enclosure. When the animal exits the passageway into the enclosure, the door falls by gravity on the entrance end of the tilting floor to reset the trap and the raised end of the tilting floor limits the ability of the captured animal to return to the passageway. Such a trap is representatively described in co-pending application Ser. No. 09/729,832, filed Dec. 6, 2000 (the '832 application), which is incorporated herein by reference in its entirety.
Captured animals will attempt to escape in any way possible. When rodents are caught in the enclosure, they often try to grasp the inner end of the tilting floor to regain access to the passageway. In some instances, rodents on the tilting floor have been able to grasp the side of top edges of the door with their claws or teeth to pull the door down against their own weight, and thereby escape from the trap.
In order to prevent escape when live capture of the animal is not desired or needed, as in the case of vermin, animal traps have been developed which include electric or electronic components to kill the trapped animal. Many of these traps, however, have very complicated structures which are costly to manufacture. Additionally, these traps are not conveniently employed without disruption of the animal's environment nor are they able to control the voltage to the trap. Some are designed to provide continuous power which is not cost effective, and others cannot keep the animal in the trap, because the animal can grasp the top of a side edge of the trap door and scratch or chew its way out.
In U.S. Pat. No. 5,269,091 to Johnson et al, a flexible plate is charged with a base plate. Upon entry into the trap, the pest presses the flexible plate into contact with the base plate, completing the circuit and applying a high voltage to the pest. The problem with this type of device is that voltage is applied only when the pest makes contact with the flexible plate. In many cases, when the pest is initially shocked it will move and not receive enough of a shock to exterminate it. As there is no trap door, the pest can readily escape, thus defeating the purpose of the trap.
In an attempt to solve the previously noted electrical problem, U.S. Pat. No. 5,949,636 to Johnson et al discloses a portable pest electrocution device with a resistive switch trigger. The device has a resistive switch to sense the presence of a pest between two electrodes. One of the electrodes is set at a high voltage and the other is set to ground. The ground electrode is a separate stake-shaped electrode which is placed physically in the ground. When the pest enters the trap, contact is made, and a timer begins for a set period of time. After timing out, the timer deactivates the power to the electrodes. A problem with this device is that a separate ground stake is necessary which, if forgotten or misplaced, renders the device inoperative.
The trap of copending application, Ser. No. 10/043,161, filed Jan. 14, 2002 (the '161 application), which is hereby incorporated by reference in its entirety, has been designed to overcome the defects in the prior art and provides a virtually escape-proof animal trap with many advantages. Not only is the animal electrocuted effectively, but the device set forth in the '161 application also provides a visual indicator signaling when the trap has initiated a kill cycle and thereafter requires servicing to remove an electrocuted animal.
Other trap designs that have effectively overcome the pest-escape defects in the prior art are set forth in copending application, Ser. No. 10/320,688, filed Dec. 17, 2002 (the '688 application), which is hereby incorporated by reference in its entirety. Eliminating the need for a tilting platform, the diverter traps disclosed in the '688 application advantageously substitute at least two fixed barriers or diverter members that are positioned between the opening of the trap and a pair of spaced charge plates electrically connected to a voltage source. The two charge plates are configured such that contact with both charge plates simultaneously by a target animal will actuate the electric charge to effectively kill the animal.
However, a problem still exists in that, while the trap may have been triggered by an animal so as to initiate the kill cycle and subsequent entry into a standby mode requiring service to reset the trap, the animal subjected to the voltage may not have been killed and may have escaped. As a result, wasted effort is expended by exterminator personnel or other users in servicing and resetting a trap which, in fact, is already empty.
Therefore, a need exists for a trap that combines an electronic circuit for effective pest electrocution with a detection mechanism to rearm the trap without human intervention in the event of pest escape.